In 1967 forgeries of the Australian $10 note were found in circulation and the Reserve Bank of Australia was concerned about an increase in counterfeiting with the release of colour photocopiers that year. In 1968 the RBA started collaborations with CSIRO and funds were made available in 1969 for the experimental production of distinctive papers. The insertion of an optically variable device (OVD) created from diffraction gratings in plastic as a security device inserted in banknotes was proposed in 1972. The first patent arising from the development of polymer banknotes was filed in 1973. In 1974 the technique of lamination was used to combine materials; the all-plastic laminate eventually chosen was a clear, BOPP laminate, in which OVDs could be inserted without needing to punch holes.
An alternative polymer of polyethylene fibres marketed as Tyvek by DuPont was developed for use as currency by the American Bank Note Company in the early 1980s. Tyvek did not perform well in trials; smudging of ink and fragility were reported as problems. Only Costa Rica and Haiti issued Tyvek banknotes; test notes were produced for Ecor, El Salvador, Honduras and Venezuela but never placed in circulation. Additionally, English printers Bradbury Wilkinson produced a version on Tyvek but marketed as Bradvek for the Isle of Man in 1983; however, they are no longer produced.
*Some additional information taken from Wikipedia for education purposes only.